The present invention generally relates to apparatus and methods for controlling microbial nitrification and more specifically, to apparatus and methods for providing a dose of ultraviolet-A (UVA)/Visible light in covered drinking water storage facilities to control nitrification.
It is well established in the scientific literature that the enzymes used by nitrifying microbes to first oxidize ammonia to nitrite and then nitrite to nitrate are inhibited by UVA and visible light. Potable water is often stored in large water storage tanks. Nitrifying microbes may produce nitrites and nitrates through the oxidation of ammonia produced by the degradation of chloramine disinfectant.
In covered drinking water storage, nitrification contributes to the loss of disinfectant residual, stimulates the growth of other nuisance microbes and produces nitrite and nitrate, both of which are regulated drinking water contaminants. Nitrate is the cause of methemoglobinemia (blue-baby syndrome) in infants.